1. Field of the Invention
The present invention relates to various members used in semiconductor manufacturing equipment and liquid crystal manufacturing equipment, particularly to component parts of etching apparatus, CVD apparatus or the like such as inner wall material (chamber), microwave introducing window, shower head, focus ring and shield ring, component parts of cryopump, turbo molecular pump or the like used in such equipment to achieve a high degree of vacuum and, especially among these, parts that are required to have high corrosion resistance against corrosive gases and plasma thereof.
2. Description of the Related Art
Quartz and sintered aluminum oxide have been commonly used for making members of semiconductor manufacturing equipment and liquid crystal manufacturing equipment that are exposed to plasma in corrosive halogen gas atmosphere including fluorine and/or chlorine, such as inner wall material of vacuum chamber, microwave introducing window, focus ring and susceptor.
In recent years, however, it has been proposed to coat the surface exposed to plasma in corrosive halogen gas atmosphere including fluorine and/or chlorine with an oxide or a fluoride of a compound of the group 3 element for making a member that has high resistance against corrosion, instead of quartz and sintered aluminum oxide.
More recently, it has been proposed to use the conventionally employed material as the base material and form a corrosion resistant coating or a corrosion resistant layer thereon thereby to make use of the properties of the conventionally employed material and improve the corrosion resistance thereof, rather than forming the entire member that is exposed to corrosive halogen gas atmosphere including fluorine and/or chlorine from a corrosion resistant material.
As the method for forming the corrosion resistant coating or the corrosion resistant layer described above, thermal spraying method has been dominantly employed. In the thermal spraying method, a material having higher corrosion resistance than the base material, that is melted by means of a heat source such as plasma, is sprayed from a nozzle in the form of fine particles and is caused to deposit and solidify on the surface of a base material made of ceramics or a metal, so as to form the corrosion resistant coating or the corrosion resistant layer.
As an apparatus that uses a corrosion resistant coating or the corrosion resistant layer formed by the thermal spraying method, such a processing apparatus is disclosed that comprises a processing vessel containing a substrate to be processed in the manufacture of semiconductor, and a processing mechanism for processing the substrate in the processing vessel, wherein the processing vessel is lined with a coating containing a compound of the group 3 element of the periodic table, on the inner surface thereof, and the coating is formed by the thermal spraying method (see Japanese Unexamined Patent Publication (Kokai) No. 2001-226773).
Also disclosed is a member resistant to halogen gas plasma that is exposed to the plasma of halogen gas, comprising a main body and a corrosion resistant film formed on at least the surface of the main body, wherein the corrosion resistant film that is formed by thermal spraying method adheres to the main body with peel-off strength of 15 MPa, and is subjected to a heat treatment at a temperature from 1400 to 1600° C. in order to make the film denser (see Japanese Unexamined Patent Publication (Kokai) No. 2002-249864).
Moreover, it is disclosed that an complex oxide ceramics material is formed by thermal spraying of a plurality of amorphous material at a temperature of 800° C. or higher and lower than the eutectic temperature of the component, thereby to precipitate crystal particles of a plurality of kinds measuring from 10 nm to 10 μm across (see Japanese Unexamined Patent Publication (Kokai) No. 2003-328107).
Also thermally sprayed film and member having the thermally sprayed film have been disclosed developed for improving the adhesion of the thermally sprayed film to the base material, strength, corrosion resistance, wear resistance and/or durability of the thermally sprayed film by mixing various materials and using the composite material in the thermal spraying method, or by filling pores of the thermally sprayed film formed on the base material made of a metal or other material with a filler thereby to make the thermally sprayed film denser (see Japanese Unexamined Patent Publication No. 2000-355752, Japanese Unexamined Patent Publication (Kokai) No. 2001-131730, Japanese Unexamined Patent Publication (Kokai) No. 2001-152307, Japanese Unexamined Patent Publication (Kokai) No. 2001-152308).
For the corrosion resistant film described above, PVD corrosion resistant films formed by various variations of PVD method that enable it to obtain corrosion resistant films that is denser than the thermally sprayed film have been employed in addition to those formed by the thermal spray method (see Japanese Unexamined Patent Publication (Kokai) No. 10-4083).